iOS UI & Layout

iOS UI & Layout Standards

Priority: P0

Implementation Guidelines

Auto Layout

• Code-Based Layout: Prefer programmatic layout using NSLayoutAnchor or SnapKit over Storyboards for better source control.
• Safe Area: Always respect view.safeAreaLayoutGuide.
• UIStackView: Use for linear layouts to reduce constraint complexity.

UIKit Best Practices

• View Lifecycle: Perform layout adjustments in viewWillLayoutSubviews or updateConstraints.
• Reusable Views: Extract complex UI into custom UIView subclasses.
• Image Optimization: Use SF Symbols for icons. Preferred vector (PDF/SVG) for custom assets.
• SwiftUI Bridge: Use UIViewRepresentable or UIViewControllerRepresentable to host UIKit in SwiftUI.

Human Interface Guidelines (HIG)

• Accessibility: Support Dynamic Type and provide meaningful accessibilityLabel.
• Feedback: Use UINotificationFeedbackGenerator for haptic feedback on actions.
• Margins: Follow standard system margins (typically 16-20pt).

Anti-Patterns

• Hardcoded Frames: **No CGRect(x:y:w:h)**: Use Auto Layout.
• Pyramid of Constraints: **No complex constraint logic in VC**: Use UIStackView or custom views.
• Missing Loading States: **No Blank Screens**: Use skeleton views or UIActivityIndicatorView.

References

• Auto Layout & HIG Compliance